Field of the Invention
The present invention relates to a resistive random access memory (RRAM), and especially relates to a switchable read operation of RRAM and the manufacturing and the control methods thereof.
Description of the Related Art
A resistive random access memory (RRAM) usually includes a plurality of memory cells each having a transistor and a resistor, in which the memory cell can be biased by an external voltage to change the resistance of the resistor so as to be written or erased. That is, the memory cell can be switched between a high-resistance-state and a low-resistance-state to represent different digital information (‘0’ or ‘1’). The RRAM memory cell not only has a simple structure, but also can be manufactured in a stacked manner for high cell density. Furthermore, the operation voltage of the RRAM memory cell is quite low; therefore, RRAM is a very promising memory technology.
The read/write characteristics of the memory cells may be failure if the memory cells are accessed frequently, such that the digital data stored in the memory cells cannot be read out normally. Furthermore, semiconductor components such as RRAMs are usually tested for reliability under high-temperature conditions, for example, 85° C. These high-temperature reliability tests may also damage the read/write characteristics of the memory cells.